| Many devices with different principles， such as current meters， float-type measurements， non-contact current meters， have been used to conduct discharge measurement. Among them， acoustic Doppler devices with a profiling technique loaded on boats are the only tool capable of water discharge measurement without any hydraulic assumption. In 1981， Acoustic Doppler Current Profilers (ADCP) were developed by RD Instruments Inc. initially for marine measurement， but have been also applied by many river engineers to river discharge measurement. Since the beginning of the 2000s， the United States Geological Survey (USGS) has developed criteria for Quality Assurance (QA) as well as guidelines associated with ADCP measurement. However， they are not easily applicable to flood flows， for example， in Japanese rivers， characterized by high unsteadiness， loose boundary， and， above all， rough water surface. Therefore， we have developed an ADCP measurement system as well as concept of QA which are suitable for measuring in Japan. Finally， we compiled them as the water discharge measurement method using ADCP in Japanese rivers. |
